Baby poop can take on a number of colors and consistencies. At some point, you may notice that your baby has green poop, and here’s the thing: Green poop may indicate a health problem, but it could also be perfectly normal. Learn how to tell the difference between green baby poop that requires medical attention and green poop that does not.

What causes green poop?

Normal baby poop can range from yellow to green to brown. For babies, the biggest factor that influences poop color is the time it takes the poop to pass through the baby’s system. Bile is secreted by the liver, which aids in digesting fats and causes yellow poop. When poop passes through the intestinal tract at a rapid pace, it causes green baby poop. When passing at a more normal pace, poop will be yellow or brown.

Frothy green poop: Breastfed babies may have green poop that looks frothy due to an excess of foremilk in their diet. Foremilk is the milk that a breastfed baby receives first, and it has a much lower fat content. If your baby’s poop is green and frothy, they may need more hindmilk, the higher-fat milk that comes later during breastfeeding.

To ensure that your baby is getting plenty of fat from hindmilk, be sure to empty one breast completely before switching to the other. This may take some patience on your part, especially in the beginning when breastfeeding is still being established. If you suspect that your baby is not getting enough hindmilk due to frothy green poop, or if you’re having trouble breastfeeding, reach out to a lactation consultant.

Bright green poop with mucus: Sometimes when your baby is drooling a lot, some mucus may be present in their poop. However, when mucus is present in a baby’s diaper for more than two days, this could be an indication of an allergy or infection. The mucus will usually appear as slimy, glistening strings in the diaper. You should notify your pediatrician if mucus is present in your baby’s poop, especially when it’s accompanied by any other symptoms.

When should you be concerned about your baby’s green poop?

Baby’s first poops — called meconium — will be a black color, but within a couple days after birth, the color will transition to a light green color. From there, the poop should gradually darken. The occasional green poop baby exhibits is usually nothing to worry about, but if the poop remains consistently green for days or weeks at a time, visit a pediatrician to ensure that there are no underlying health conditions to address.